Spain's Anabel Medina Garrigues defeated qualifier Melanie Oudin 6-4, 4-6, 6-0 on Monday as the main draw action got underway at the WTA Tour's Charleston tournament.
Medina Garrigues, who at No. 10 was the top seed competing, advances to the second round of the clay court event where she will face Australia's Anastasia Rodionova who beat qualifier Melanie Czink 6-2, 2-6, 6-1.
Clay court specialist Medina Garrigues has won 10 WTA titles on the surface, more than any other active player.
Medina Garrigues finished with one ace, one double fault and won 62 percent of her first serve points in the two hour, 29 minute match.
Former US Open quarter-finalist Oudin had two double faults and won 54 percent of her second-serve points.
Unseeded Canadian Aleksandra Wozniak outlasted American 11th seed Christina McHale 7-5, 5-7, 6-4 in a two hour, 48 minute marathon match.
Wozniak, a former world No. 21, fired three aces and won 70 percent of her first-serve points.
In other matches Monday, No.14 seed Polona Hercog cruised past Japanese veteran Kimiko Date-Krumm 6-4, 6-3; Argentine up-and-comer Paula Ormaechea surprised No. 15 seed Chanelle Scheepers 6-1, 1-6, 6-4; and No.16 seed Jarmila Gajdosova lost to Swiss qualifier Stefanie Voegele 6-4, 2-6, 6-4.
Former winner Serena Williams begins play on Tuesday against Elena Vesnina of Russia, who beat Canada's Stephanie Dubois 7-6 (12/10), 7-5.